3.Duct Work
(1)All series units are equipped with horizontal supply and return air openings. Duct connection to the unit should be made with duct flanges and secured directly to the air openings with flexible duct connectors to avoid normal noise transmission.
(2)For vertical air supply, a field supply plenum should be used.
The figure below shows the recommended method for duct connection.
(3)To prevent air leakage, all duct seams should be taped.
Ducts run in air spaces that are not
(4)Where ducts from the outside enter a building, the duct openings in the building should be sealed with weather stripping to prevent rain, duct, sand,etc. from entering the building.
(5)Correctly sized filters must be fitted and there is no provision within the unit, however the filters may be installed in the return air.
4.Drain piping
PRH unit | Vertical air | |
| plenum | |
Plenum |
| |
divider |
| |
| Insulation | |
Roof curb | Roof curb | |
| ||
Duct Singleduct | Roof line | |
Duct | ||
divider |
Duct connection with a vertical air plenum
(1) A 1 FPT condensate drain fitting is provided. The |
drain pipe can be led out at the right or left side. |
Under standard specifications, it is led out at the left |
side and the right side is covered. |
(2) The drain pipe must be provided with a trap on the |
outside of the unit and also installed at an incline for |
proper drainage, as shown below. |
A=>70mm B=>2C C=>2XE.S.P
A C
Drain trap
B
Drain piping
The drain pipe should extend below this level.
(3) To prevent condensate formation and leakage, |
provide the drain pipe with insulation to safeguard |
against sweating. |
(4) Upon completion of the piping work, check that there |
is no leakage and that the water drains off properly. |
Note:ESP=External Static Pressure
Drain trap for condensate
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